Process and apparatus for treating milk



C. M. PETERSON PROCESS AND APPARATUS FOR TREATING MILK Filed Jan. 9, 1924 2 Sheets-Sheet 1 4 L N M Him. Q l: l/vvE/v r01?' 2 Q q 0mm M. PETE/750M.

2 Sheets-Sheet 2 c. "M. PETERSON PROCESS AND APPARATUS 'FOR TREATING MILK Filed Jan. 9,1924

July 15'. 1924.

In VE N Tali. 611/715 M. F5 TEfi50/V. 8) 5, f7 7' T 0/7NE Y.

I yaw W19? Minneapolis, in the county of Hennepin and. v

Patented July 1 5, 1 924.

/ UNITED- STATES" cams M. rn'rnnson, or MINNEAPOLIS, MINNESOTA.

PROCESS AND APPARATUS roa REATING MILK.

- App1ication filed-January 9, 1924. Serial No. 685,154.

To all iuhom it may concern Be 1t known that I, CHRIS M. PETERSON, a citizen of the United States, residing at State of Minnesota, have invented certain new and useful Improvements in-- Processes and Apparatus for Treating; Milk; and 'I do hereby declare the following to-be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invent-ion relates to'a method and substances to dry finelydivided form, and while the invention is applicable to many substances, it particularly is designed for use with milk or buttermilk. At present the milk drying methods "and devices can be classified, generally, into'two classes those which'spray the milk into a gaseous medium', such as heated air, and those which 'dry the milk on heated surfaces from which it'is removed and pulverized.

he most difficult problem with the drum drying machines of the prior art has been that of getting the film or layer of milk onto the drum. in all of these machines that depend-on the heating drum for the drying operation, the milk has heretofore gent y against the drum, the surplus not ad- I he-ring to the drum being caught and retained in the pan. The capacity-of the drum drying machine has heretofore been .quite limited on account "of not being able to secure the deposite of a good film of milk on a highly heated drum. In the machines where the milk is brought gently against the drum, if the drums areheated beyond a1 point corresponding to fifteen pounds pressure of steam, themilk would not adherev to the drum in suiiicient quantities to make I the machine practically operative. The tendency of liquid not to adhere to a heating surface is quite well known and most people have seen liquids bubble and run off-of a hot stove or other heated metal surface. Where the heat of the drum is limited, the

globules of the milk are finely speed-of the drum is limited as the milk must-be dried in a practical operative ma-- chine. Another objection to a highly heated drum has been that themilk will scorch thereon, the drum.

It is an object of the present invention therefore, to provide a novelmethod and apparatus for insuring an eificient adhesion if allowed to rest in contact with of the milk and drum when the latter is highly heated so that the milk can quickly be dried and the drum rotated'at compara- 'tively high speed. apparatus for-reducing fluidor semi-fluid,

pressure and then discharged and projectedat such pressure through a nozzle having a small aperture whereby the fat and liquid broken up and the milk homogenized, t e projected milk in such condition being received upon a moving heated surface whereby it instant-- 1y adheres to said surface and is quickly 7 dried.

It is an object of the present invention to provide an improved method and appara tus for drying the fluid on a heated movin surface whereby a' much larger amount '0 fiuidcan be dried in a given time. 1 [It is a further-object of the invention to provide such a method in which the milk is. sprayed under high pressure in a time e.t

against a heated moving surface forming a film thereon which is driedand then removed from said surface. a It is-also an object ofthe invention to provide an apparatus comprising a heated moving the resulting film from-said surface when it is dried.

vide such a heated moving surface preferably in the form of a revoluble-drum, to-

It is also an object of the'invention toprogether with means for spraying the milk ina fine jet thereon, and a member disposed in close proximity to said surface and ex-' tending across the same to reduce or eliminate the bubbles which might arise from the film on said surface:

moving surface, and means for spraying the milk-under ressure ma fine et against said -moving surface, together with means for re- It is more specifically an object of the invention to provide an apparatus comprising a pair of parallel heate drums with their surfaces su stantially in contact at one point, which drums revolve toward each other, to-

' getherwith a plurality of nozzles extending along said drums, respectively, in advance of said point of contact, forforcibly projecting the milk thereon under pressure, and means for removing the dried milk from said drum, which apparatus may be enclosed rows;

ill)

same parts throughout the different views.

in a chamber into which a can be produced. 1

These and other objects and advantages of the invention will be fully set forth in the following description made in connecpartial vacuum ,tion with the accompanying drawings in which like reference characters refer to the i another modified form of apparatus;

' for; and

Fig. 6 is a view in vertical section of a nozzle used showing the-supply pipe there- Fig. 7 is a view in side elevation of a portion of said nozzle. Figs. 6 and 7 being shown on an enlarged scale.-

In carrying out the method of the invention, the milk ,is received and stored in a' suitable tank 1 from whence it passes throughthe pipe '2 controlledby the valve 3 to a heating device 4. The heating device 4 may be of any suitable standard'and well known form of heating device. the same being shown diagrammatically in the draw- .ings and comprising a steam pipe 5 through which steam IS passed in the direction indicated by the arrows to a coil or heating member connected to. the plurality of rotating heating members contained in the device 4 which are rotated by means of a pulley which is controlled by the valve 15, com

municates with two branch pipes 16, each of which is controlled by a valve 17. Connected to and depending from the pipes 16 are spaced pipes 18 which are equipped with delivery nozzles 19 at their lower ends adapted to deliver-the fluid in a fine jet. The delivery nozzles 19 are disposed above and spaced some distance from a air of "drums 20. The nozzles are of specia construction and, in connection with the pressure used, 7

gears 22 secured at the ends thereof, which are, in turn, driven by worm gears 23 secured to a shaft driven by a suitable pulley 24. Steam pipes 25 and 26 pass axially into and out of the drums 20 and are adaptplg steam to the interior of said 35 drums for eating the same.

ed to sup The nozzles 19 are disposed in a substantial vertical alinement with the axis of said drum, in the embodiment of the invention illustrated, the

same being shown as disposed slightly at the outside of said vertical axis. A scraper blade 27 is swingingly mounted about a shaft 28 extending along the top of thefranie 21 and journaled in suitable bearings secured at the ends thereof. The free edge of said blade 27 being beveled and sharpened, will lie closely against the outer surface of the drum 20 and said blades are adjustable toward and from the drum by screws '29 carrying hand wheels 30, said 10c screws passing through suitable nuts secured in a bar 31 extending lengthwise of the frame 21. As shown in Fig. 3, there'is a blade 27, shaft 28 and a plurality'of adjusting screws for each of the drums 20, thelower edges of said blades contacting the said drums outwardly of the nozzles 19 in advance of said nozzles relative to the direction of rotation of said drums. The drums or rollers 20 have their peripheral surfaces thereof and preferably are equipped with screw conveyors 33 extending lengthwise 6. The milk, or other fluid to be dried} therein. passes from the device 4 through the pipe 7 der considerable pressure and the pipe 14,

The structure of the nozzles 19 is shown in detail in Figs. 6 and 7, in which it will be seen that each nozzle 19 is formed as a.

sleeve threaded onto the pipe 18 and having a small central aperture 19 in its closed end. A plug or block 19 is disposed in the sleeve 19 and substantially fits in a cylindrical recess in the bottom thereof. Said plug 19" is equipped with helical grooves in its per pheral surface 19 disposed at opposite s1 es thereof and extending from the top tothe bottom of said plug. The plug 19" also has a semi-spherical recess 19 in its the nozzles comprising a multiplicity of very fine particles.

In carrying out the method of the present invention in the apparatus described, the

' milk will be heated in the heating device 4 and will be furnished under pressure to the pipes 16 and 18. A pump having a plurality of plunger is used so that a substantially uniform pressure is obtained. Steam will be passed into the drums 20 and said drums rotated toward each other in the direction indicated by the arrows in Fig. 3 by power applied to the pulley 24. The valves are now open so that the milk willbe projected in fine jets from the nozzles 19 onto the peripheral surface of drums 20. The milk forms av thin film on said heating drums and passes around the same. Any bubbles rising in the film will be eliminated or reduced as the surfaces of the drums pass the point of their closest proximity and the film of milk will be uniform on said tothe drum and is drums after passing said point. The film of milk is retained on the drums'nntil it reaches the blades or members 31, by means of which it is scraped from the drums and falls into the troughs 32. From the drums 32 the milk which is now in dried form, is conveyed to suitablegrinding or pulverized apparatus. This pulverizing operation and apparatus are well known and old in the art and the same are not illustrated. -By spraying the fluid'or milk forcibly against the surface of the drums 20, an intimate contact is obtained between the milk and said surface and said milk instantly sticks is practically no bub ling of the milk or. the film on said surfaces. It is well known that if a drop of water is dropped ontoa heated surface, that it does not stick to said surface but glides about and bubbles on the same. This action is eliminated in applicants process.

By having the milk under pressure and projecting the same under pressure in.a fine jet through the small aperture in the nozzle 19. a homogenizing effect is had thereon and the fat and liquid globules are finely broken up so that the milk instantly adheres to the surface of the drums or cylinders and quickly is dried. A very intimate contact is thus obtained etween the uickly dried. There milk and the surface of the drums. A pressure of from 500 to 2,300 pounds per square inch is placed on' the milk during thespraying operation. If any bubblcsdo rise on thefilm, as stated, they are eliminated by passing between the rollers where they are most nearly in contact.

.With applicants method and apparatus, the drums can'be heated to a higher degree and rotated more rapidly than with the prior methods and apparatus where the milk was merely gently discharged against or poured above the rolls at their points of contact. The maximum production on one of the prior double drum machines using the prior method was 33 pounds of dried milk per hour. \Vith the present method and apparatus, thispro'duction has been increased to a maximum of 123 pounds per hour. It will thus beseen what a great advance applicant has made in the drying art.

In Fig. 4 an apparatusis shown in which the drums 20, nozzles 19, pipes 18 and 16 are also used .in connection with the other apparatus shown in Fig. 1. A casing 34, however, extends about the drums, blades 27 and pipes 16, 18 and 19, the milk being supplied to the pipe 16 by the pipe 15 which passes through the casing 34. Troughs 34 are formed at the outer sides of and below the drums 20 having therein the conveyors 35. The casing 3 1- is made air tight and accomplished by the partial vacuum as Well as by the heating drums 20. With the vacuum chamber formed-by casing 34 the boiling point of the milk can be lowered therein so that the milk is dried without being exposed to as high a temperature as where the vacuum chamber is not used.

In Fig. 5, a device is shown comprising only one roller 20 mounted'in a-suitable frame 36. which roll is equipped with the blades 27 and adjusting screws 29 already described. The milk is delivered to the drums 20 through the nozzles 19 and pipes 16 and 18 in connection with the other apparatus shown in Fig. 1. The milk removed by the blades 27 will be collected in the trough 37. V A member 38 extends longitudinally ofthe drums 20 ,in close proximity thereto and when the milk-is sprayed onto the drums. as above described, said member 38 will act as does the other roll20, to eliminate or reduce any bubbles which might arise in the film and to insure a uniform filmon the drum. While the member 38 may take various forms, in the embodiment I of. the invention illustrated, it is shown as being used is between 500 pounds and 2,300

pounds per square inch, more or less eflicient results could be obtained with a lower 7 pressure, especially by decreasing the speed of the drum .or drums. The invention comprises any considerable pressure adequate to forcibly project the milk in a minute jet onto the heated drum. i

It will, of course, be understood that vari- --ous changes may be made in the form, de-

. '1. The method of drying milk or tails, arrangement and proportion of the apparatus, as well as in the steps and sequence of the steps of the method,.without departing from the scope of applicants invention, which, generally stated, consists in a deviceand method capable of carrying out the objects above stated. such as shown and described and set forth in the appended claims.

What is claimed is:

other fluid or semi-fluid materlalcom rising placing the milk under pressure, fhrcibly projecting the milk under pressure in a series of minute jets against a heated surface to form a thin film on-said surface, retaining said film on said surface until'the same is dried, and then removing said film from said surface.

2. In a method of dryin milk or other fluid. or semi-fluid materia, the steps of placing the material under pressure, and forcibly projecting the material under pressure in a series of minute jets against a heated surface to form a thin'film on said surface;

3. The process of dryin milk or similar. fluid or semi-fluid materia comprising placmg saldmilk under pressure, passi :"said milk through a series of minute disc arge openings under pressure to break upthe fat and liquid globules whereby said. milk is homogenized Land receiving said milk so projected upon a heated surface whereby -said milk adheres instantly to'said surface permitting said milk to remain on said-surface until substantially dry and then re,-

"moving the same from said surface.

4. The method of dryin milk or similar material consisting in p acing said milk, under pressure of fifty pounds per square mch or more, projectmg said milk under said pressure in a series of minute jets into contact with a heated movable surface whereby it. instantly adheres to said surface, retaining said material on said surface until dry and then removing the same from said surface.

5. The method of producing dried milk or similar material which comprises heatmg the milk, placing the same under pressure and projecting the milk under pressure in a series of minute jets against a moving heated surface to form a thin film thereon, passing said film and surface in close proximity to a member extending thereac'ross, to'bring said film to substantially a uniform thickness, retaining said film on said surface until the same is dried and then removing .said' dried milk from said surface.

member having a movable peri heral surface, means for heating said sur ace, means pro ectmg and milk at said pressure 1n a mu tlpliclty of mmute ets against said surface to form a film thereon, means for re-- moving said film from said surfacewhen dry,,and a casing surrounding said member and adapted to have a partial vacuum formed therein. 1

8. An apparatus for drying milk or other fluid material comprising means for plac-' ing the milk under ligh pressure, a member 6. An apparatus for drying milk or other having a movable peripheral surface, means for heating said surface, a conduit connected with said first mentioned means having a series of nozzles extending therefrom disposed along said surface, said nozzles havmg minute discharge openings and bemg spaced from said member whereby said milk is discharged at said hlgh pressure from said nozzles against said member and adheres thereto and is dried, and means ,for

removing said material from said member. 9. 'The structure set forth in claim 5, and I means extending in close proximity to said drum past whic said film travels to reduce any bubbles rising thereon.

' 10. An apparatus for drying milk or other fluid or semi-fluid material having in combination, means .for placing the milk under pressure, a pair of-parallel revoluble drums aving thelr peripheral surfaces in close proximity and revolving toward each other,

5 a plurality of nozzles extending lengthwise of each drum in advance of their line of close proximity and having minute discharge openings adapted forcibly to project minute jets of milk against said drums, respectively, to form a thin film thereon, iheans for heat- 1 ing said drums, vand means in advance of said nozzles for removing the film when dry from said drums.

-In testimony whereof I afiix 'my signature. y

CHRIS P TERSON. 

